Sound-modifying means for sound transmitting and reproducing machines



Patented Aug. 16, 1927.

UNITED ySTATES WILLIAM ORE, or MEMPHIS, TENNESSEE.

SOUND-MODIFYING IMEIIUAMWSk FOR SOUND TRANSMITTING AND REPVRODUCING MACHINES.

Application filed March 29,1924.' Serial4 No. Y702,895.

My invention` relates to sound modifying devices for instrumentalities adapted to transmit or record the sounds of the voice,

such as dictating phonographic machines telephones and speaking tubes.

`The objects of the invention areto provide means wherebythe sound of the voice of the person speakinginto the mouth piece of the instrument is prevented from being audibleto others near the speaker with the resulting advantage of enabling dictation and telephoning to be carried on without the disturbance of others in the same room with the speaker and insuring privacy in the yrecording ortransmitting of the message. A particularly advantageous use of the invention is in the report of proceedings in a court room yor a convention by direct vocal repetition of the spoken words intoy the machine instead of a record by stenographic notes, followed by subsequent transcription or dictation.

Another object of the `invention is to clarify the tones of the voice vibrations so that `a clear and distinct record and reproduction of the voice sounds may be obtained.

With these vobjects yin view, my invention is embodied in `preferable form in the con-` struction hereinafter described and illustrated in the accompanying drawings.

In these drawings- Fig.` l is a longitudinal section throughV the sound tube and mouthpiece embodying the invention; and

Fig. 2, a cross section online 2-2 of Fig. l. l

Referring to the drawings7 l indicates the usual flexible tube adapted to extend to the sound receiving` diaphragm box of a dictation recording machine.. This tube may, in use in connection with a telephone, be replaced by the diaphragm holder of the telephone. Gonnected to and communicating with this tube l is a transmitter 2, comprising a tubular body surrounding at one end thereof the tube l and formed preferably of an outer tubing 3 of rubber or other flexible material within which is secured a lining 4, preferably of a material which is a nonconductor of sound. The outer end vof the barrel of the transmitterl terminatesin a mouthpiece 5 adapted to fit over the mouth of the speaker.

Placed loosely within the body of the.

the inner end of which projects into the innner endofthetube 1. This member consists-of several tubular truncated cones 6 of tin coiled or curved circularly and of progressively increasing size from the inner to the outer 4element and loosely nested one within the other;` Two are shown but a greater number may bey employed if found desirable. This device acts as a sound modi-v fying means, its probable action being to exert` a drag or impedance to the resonance of the tones of the voice through the presi sure .of the sound waves against the tubular elements, plus a decrease in the volume of sound waves emerging from the inner end of the funnel, Vdue to its tapered or cone shaped formation. f

Surrounding` the inner end portion of the The inner end of the space between the f barrel of the transmitter and the sound co`nveying tube l has aclosure 9 vconsisting` preferably of a plug of plaster of Faris. In this closure is formed a vent l() for the es cape of air expelled from the mouth of the speaker.r The air passes from the vbarrel and inner end of the funnel member into and through the cotton. Vmits a circulation of air through the device.

The sound waves of the voice escape from the inner end of the mouth tube and from the multiple non-resonant and impedance tubular member fall on the cotton placed in the lower section of the tubing and are partly absorbed thereby.

That I claim is:

l. A. transmitter for speech reproducing devices having a barrel of non-resonant material, a mouth tube, a sound conveying tube with which said mouth tube is connected, a closure between the walls of said tubes, a series oftapered coiled members of nonresonant material nested one within the other and mounted loosely within said mouth engaging tube and projecting into This vent also per said sound conveying tube, and a lpacking of fibrous material between the barrel ot the mouth engaging,r tube and the sound'con- Veying tube and adjacent the innerlend of: said nested tubular members.

2. A speech transmitter comprising a tubular mouth member, a tubular element ot non-resonant material axially disposed Within the tubular mouth member, said tubular element tapering away from the outer end ot the tubular mouth member.

37A speech transmitter comprising a tubular mouth member and a plurality oi loosely nested tubular elements'axially supported vithin said tubular mouth` member and tapering away from the mouth end oit the tubular mouth member.

4. A speech transmitter comprising an elongated tubular mouth engaging` member, a plurality of nested tubular members axiallyssupported Within the mouthmember, said nested tubular member being` coiled in form, and formed of non-resonant metal.

A speech transmitter' comprisingan elongated tubular mouth engaging member, a member axially disposed and supported Within said mouth engaging member, said axially disposed member comprising a plurality of coiled cone shaped members nested together and formed of metal and u sound conveying tube extending into the end ot the mouth engaging member and in which the coiled cone shaped Vmembers terminate.

6. A speech transmitter comprising a tu bular mouth engaging member, a tapered tubular member axially disposed and supported within the mouth engaging member and a fibrous sound damping; member Within the tubular mouth engaging member and adjacent the end ot the tubular member.

7. A speech transmitting` device comprising an elongated mouth engaging tubular member, an apertured lugl in one end ot the mouth engaging' member, a sound conveying tube extending' through said plug and into the mouth engaging; member, a sleeve surrounding` said sound conveying tube in spaced relation thereto and secured to the tube, a fibrous material surrounding the tube Within the sleeve, a fibrous material surrounding the sleeve and interposed betreen the sleeve and the mouth engaging tube and an axially disposed tapered memn ber Within the mouth engaging tube and having` its end disposed Within the end oi' the sound conveying' tube.

in testimony Whereo't l affix my signature.

VILLIAM OBR. 

